Packages are used to contain and protect a substance until it is desired to release the substance from the package. Packages may be used to contain various solid substances or articles, such as powders, pills, granules and other shaped substances. Packages may also be used to contain various flowable substances such as gels, solutions, dispersions, and other dimensionally unstable substances. In some cases, it may be desirable to include structure on the package which assists in dispersing or applying the contents.
Several factors are taken into consideration in providing a package system for dispensing a flowable or solid substance. One concern is the performance characteristics of the dispensing package. For example, the ease with which the package can be opened and its contents expelled can be important. The ability of the package to store and contain a substance prior to its application is another factor. When an applicator is included as part of the package, secure attachment of the applicator to the packaging can be important so that the applicator does not become disengaged during use.
Another consideration in designing a useful dispensing system is the ability to deliver more than one substance from a unitary system. Also desirable is a packaging system that is useful to simultaneously combine and dispense a plurality of substances, each requiring separate storage until being combined, due to their physical or chemical incompatibility.
Various packages have been developed to contain and dispense solutions, dispersions or gels of various active ingredients. One such dispenser is an envelope-like package that defines an internal reservoir for containing a fluid. For example, U.S. Pat. No. 4,427,115 to Laipply, discloses a packaging device for applying various fluids to the skin. The device is made of a flexible sheet of fluid impermeable material that is folded in half and sealed around the edges in a temporary seal. The two halves of the sheet are pulled apart to break the seal and form a flat surface covered with the fluid. An absorbent pad may be adhered inside the chamber to aid in the retention and delivery of the fluid. A disadvantage of this type of package is its limited capacity. Also, the sealed edging may split open, prematurely exposing the contents. Conversely, the edges of the containing packet may be too tightly sealed so that it is difficult to open the packet in a controlled fashion. Additionally, the contents of the packet can often be squeezed out prematurely when the reservoir chambers are accidentally compressed.
Other packaging systems provide for a cup-like reservoir with a foil or paper covering that is torn off to expose the fluid or other material contained within the chamber. For example, Canadian Patent No. 613,023 to Wilson et al. discloses a creamer-type dispenser with a wide-mouthed cup and a covering sheet sealed over the mouth of the cup. The covering sheet has a tab adhesively sealed over a flat extension of the rim of the cup. The package is opened by pulling the tab of the covering sheet upward off the rim extension and inward toward the cup. U.S. Pat. No. 3,860,348 to Doyle et al. discloses a cup with a foil covering over the mouth and a liquid-impregnated sponge attached to the inside of the cup. When the covering is peeled off the rim of the cup, the sponge projects outward through the opening.
The covering lids of these packages may be difficult to remove so that during opening, the contents may spill out of the container due to the upward pulling action to remove the cover.
Packages have also been developed to expel the contents of an inner chamber through a fracture or score line in one surface of the package. The ends of the package are forced together to expand and rupture the score line. For example, U.S. Pat. No. 3,986,630 to Redmond discloses a dispensing package having a single reservoir with a pattern of perforations cut partially through the surface of one side of the package that is covered with a foil sealant.
Several applicator systems with a prescored fracture line in one surface of a package provide for reservoirs in each half of a single package. For example, U.S. Pat. No. 4,140,409 to DeVries discloses a system with a reservoir chamber in each half of an elongated package. A sponge is attached to the outside of the package. The chambers are separated by a partition formed by a prescored portion cut into one surface of the container. A channel extends through the partition to connect the two chambers. When the ends of the package are bent together, the score line ruptures and the contents of the chambers are expelled into the attached sponge.
U.S. Pat. No. 4,430,013 to J. W. Kaufman discloses a dispensing system with a reservoir chamber in each half of an elongated package. A score line extends across the width of the package in between the two chambers. Each of the chambers have a narrowed neck portion that fans out before abutting the score line. This configuration facilitates a controlled flow and distribution of the liquid contents from the two reservoirs into an attached sponge for simultaneous admixture. U.S. Pat. No. 4,812,067 to Brown et al. also provides a system that provides separate reservoir chambers in a flexible package. The chambers are compressed to rupture an internal seal in the package which urges the liquid contents into a central dispensing cavity. The ends of the package are bent backward to split open a score line in the surface of the package. Pressure on the package forces the contents to be expelled through the slit in the score line and onto a sponge attached to the outside of the package.
A disadvantage of packaging devices that release their contents by rupturing a score line in the container wall is that flexing of the package prior to use may cause the fracture line to split apart prematurely, thus causing unwanted leakage or premature dispersal of the contents. Conversely, the score line may be constructed such that it is difficult to break.
Therefore, there is a need for a dispensing system which addresses the above mentioned problems of prior dispensing systems. In particular, there is a need for a packaging system for dispensing flowable and/or solid substances which has an improved configuration for releasing the contents of the packaging that is not prone to premature rupture but provides ready dispensing of the package contents. There is also a need for a packaging that is a convenient means of dispensing flowable and/or solid substances from multiple reservoir chambers within the packaging system.